The present invention relates generally to a weld support gauge block utilized in fixing a fused distance between two welded members. More particularly, the present invention relates to a weld support gauge block for setting a fused distance between a plate portion and a hat portion of a planetary gear carrier of an automotive vehicle transmission during a welding of the carrier plate portion to the carrier hat portion, wherein the carrier hat portion has a cylindrical wall fixed with an annular end face and the cylindrical wall has a plurality of geometrically spaced window cut outs for subsequent placement of planetary pinion gears.
In most vehicles a transmission is provided in the drive train between the engine and the driven wheels. As is well known, the transmission includes a case containing an input shaft, an output shaft and a plurality of machine gears. Means are provided for connecting selected machine gears between the input shaft and the output shaft to provide a desired speed reduction gear ratio therebetween. The machine gears contained within the transmission case are of varying size so as to provide a plurality of gear ratios. By appropriate selection of these gear ratios acceleration and deceleration of the vehicle can be accomplished in a smooth and efficient manner.
Many transmission structures are known in the art for performing the above noted gear ratio selection manually, i.e., in response to some physical exertion by the vehicle driver. In a conventional manual transmission, the driver grasps and moves an upper portion of a pivotal shift lever. In response thereto, a lower portion of the shift lever is moved into selective engagement with one of a plurality of shift rails provided within the transmission. Thus, movement of the shift lever causes movement of the selected shift rail. Movement of the selected shift rails causes certain of the machine gears to be connected between the input shaft and the output shaft so as to provide the desired gear ratio therebetween.
Many transmission structures are also known in the art for performing the above noted gear ratio selection automatically, i.e., without any physical exertion by the vehicle driver. In a conventional automatic transmission, the shift rails are typically replaced by a plurality of hydraulically actuated structures. In response to predetermined operating condition, the structures cause one of the machine gears to be connected between the input shaft and the output shaft so as to provide the desired gear ratio therebetween. Automatic transmissions offer the advantage of increased convenience of use and reduced fatigue for the vehicle driver.
To provide for smooth shifting between the gear ratios many automatic transmissions utilize planetary gearing. When utilizing planetary gearing typically the planetary gears (sometimes called planet gears) are mounted on a common yoke commonly referred to as a carrier. Typically the carrier will have an annular end face which is weldably connected to a cylindrical wall, sometimes referred to as the hat portion of the carrier. Weldably joined to the cylindrical wall generally opposite the end face is an annular plate. The cylindrical wall of the carrier has typically three or four geometrically spaced cut outs. A series of planetary gears are rotatably mounted within the spaces of the cut outs. The planetary gears are rotatably mounted on shafts having one end connected with the aforementioned end face of the carrier hat portion. The other end of the planetary gear shaft is mounted to the aforementioned annular plate.
The stack height or axial length of the carrier is critical in the dimension of the transmission. Accordingly, care must be taken during fabrication of the carrier that the distance between the end face of the hat portion and the annular plate of the carrier be held to very high exacting tolerances. During carrier fabrication wherein the carrier hat is weldably connected with its annular plate a series of weld support gauge blocks are automatically inserted by the weld machine to ensure the desired distance between the annular plate and the end face. Prior to the present invention these weld support gauge blocks typically suffered excessive wear upon their removal from the windows in the hat portion cylindrical wall caused by friction of rubbing between the hat portion annular end face and the annular plate. Making the weld support gauge blocks harder did not provide a solution in that the weld support gauge blocks would tend to gouge metal away after removal from the window cut outs. Making weld support gauge blocks of softer metal prevented the gouging problem but exposed the weld support gauge blocks to the aforementioned excessive wear. Excessive wear of the weld support gauge blocks increased repair time for the welding machine operation.
It is desirable to provide a weld support gauge block for insertion and removal into a cylindrical wall window cut out of a hat portion of a transmission carrier which has a high resistance to wear while at the same time a low tendency to gouge or deform the metal of the hat portion or the annular plate portion of the carrier.
To make manifest the above delineated and other manifold desires the revelation of the present invention is brought forth. The present invention provides a weld support gauge block for setting a fused distance between a plate portion and a hat portion of a planetary gear carrier of an automotive vehicle transmission during a welding of the carrier plate portion wherein the carrier hat portion has a cylindrical wall connected to an annular end face and the cylindrical wall has a plurality of geometrically spaced window cut outs for subsequent placement of planet pinion gears retainable about shafts with opposed ends fixed with the annular end face of the carrier hat portion and the carrier plate portion. The weld support gauge block includes a first side plate having front and rear upper and lower tapered edges. The first side plate is provided for insertion into and removal from the window cut outs in the cylindrical wall of the carrier hat portion. A second side plate parallel spaced from the first side plate is also provided. The second side plate has front and rear tapered upper and lower edges for insertion into and removal from the window cut out in the cylindrical wall of the carrier hat portion. The support gauge block also has a body juxtaposed by the first and second side plates. The body has an interior cavity, a front face and a rear face. The body also has a generally central longitudinal bore with a counter bore along its end. A first roller with dual wheels positioned on a common axle is also provided. The first roller wheels are bifurcated by the body central bore and the axle of the first roller is generally positioned perpendicular with respect to the central bore. The first roller is juxtaposed between the first and second side plates and the common axle of the first roller has its extreme end mounted within blind bores of the first and second side plates. The first roller has contact with the carrier plate portion during the welding which is conducted to fuse the plate portion with the carrier hat portion. A second roller is provided positioned above the first roller. The second roller has dual wheels provided on a common axle which is positioned perpendicular with respect to the central bore. The second roller wheels are also bifurcated by the central bore. The second roller is also juxtaposed between the first and second side plates and the extreme end of the second roller axle is fitted within blind bores of the first and second side plates. The second roller wheels contact the carrier hat portion annular end face when the carrier plate is being fused with the hat portion of the carrier. Due to the rollers of the weld support gauge block of the present invention, gouging of the carrier by the weld support gauge block is inhibited. Additionally, the weld support gauge block by its roller design diminishes friction between the weld support gauge block and the carrier during the insertion and removal. Accordingly, the necessity of weld support gauge block replacement is significantly reduced.